Structural formula:

Character: This product is light yellow to light brown powder, with special smell and astringent taste. Soluble in 1 part water or ethanol, soluble in acetone, insoluble in chloroform or ether.
Quality indicators: in line with the 2012 edition of the British Pharmacopoeia and the 2013 edition of the United States Pharmacopoeia.
To use: Medical tannic acid has antibacterial, deenzymatic, astringent effects, used in antibiotics, ringworm treatment, detoxification, diarrhea and other pharmaceutical preparations, but also used in the synthesis of sulfanilamide synergistic agent
Storage: keep away from moisture and light and store sealed
Packing: plastic inner and paper drums of 25 kg net per barrel